Reactive liquid polymers have a hydrocarbon backbone with reactive groups in both terminal positions. Such liquid polymers are available with carboxyl, hydroxyl, vinyl, and amine reactive end groups. Some liquid polymers have pendant as well as terminal reactive groups.
These materials are 100% solids yet are in liquid state, contain no solvents, and have specific gravity of less than 1.0. Utility of reactive liquid polymers is largely accounted for by the reactive groups that can enter into reactions with other materials, as in a curing process that can involve chain extension and crosslinking to form solid elastomeric products.
Primary application of hydroxyl terminated reactive liquid polymers is as polyols in the formation of polyurethanes. In such reactions, a hydroxyl terminated liquid polymer is reacted with an organic polyisocyanate to form high molecular weight polyurethanes that find uses as mechanical parts in automotive, building, furniture and appliance industries.
One problem that has been observed in regards to hydroxyl terminated reactive liquid polymers is their instability on aging or their lack of shelf stability. For instance, a certain hydroxyl terminated polybutadiene liquid polymer had an original viscosity of 36,000 cps at 27.degree. C. that increased to 62,400 cps at 27.degree. C. after aging for 30 months at ambient conditions. This condition is unacceptable due to excessive viscosity that leads to processing problems and to undesirable changes in physical properties thereof.
Application Ser. No. 154,671 was filed on May 30, 1980, now abandoned, on behalf of inventors W. T. Murphy and C. D. Guiley, Jr. It is entitled "Process For Treating Hydroxyl Terminated Liquid Polymers" and discloses deactivation of hydroxyl terminated liquid polymers by treatment with an inorganic acid, such as phosphoric or sulfuric, before reacting it with an organic polyisocyanate to form high molecular weight polyurethanes. Without such deactivation, reaction products of a hydroxyl terminated liquid polymer and a polyisocyanate developed premature gellation and excessive exotherms.